Electric-motor.



H. K. SANDELL.

ELECTRIC MOTOR.

APPLICATION IILED'NOV. 7, 1911 2 SHEETS-SHEET 1.

1,087,556. Patented Feb. 17,1914

2 i792. pr/fly Press 00 U ward 3 7V! Zneases: Inventor.-

a e/00% Hem K. Sande 1,

H. K. SANDBLL.

ELECTRIC MOTOR.

APPLICATION FILED NOV. 7, 1911v 1,087,556. Patented Feb. 17,1914.

2 SHEETS-SHEET 2.

Witnesses: Inventor:

. 31%M Henr Ksmuieu, WMW- y M LJ W W Am UNITED STATES PATENT OFFICE. HENRY K. SANDELL, OF CHICAGi'O, ILLINOIS, ASSIGNOR TO MILLS NOVELTY COMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

ELECTRIC MOTOR.

I Specification of Letters Patent.

Patented Feb. 17, 1914..

Application filed November7, 1911. Serial No. 659,054.

plained in the specification and shown in.

the accompanying drawings, in which:

Figure 1 is'an elevation of a device einbodying the invention showing the same in one position; Fig. 2 is a similar view showing the device in another position; Fig. 3 is a side elevation looking at the device of Fig.

' 1 from the right; Fig. 4 is a view'partly in elevation and partly in section of the oscillating armature; Fig. 5 is a circuit dia gram of the device in the position shown in Fig. 1, and Fig. 6 is a circuit diagram of the device in theposition shown in Fig. 2.

The presentdevice was especially designed in the first instance for operating the bar which raises the dampers of the piano action in automatic or self-playing pianos,

thesedampers, as'is well understood, being normally held against the strings of the piano. by springs or their equivalent. In Figs. 1 and 2, 7 i'ndicates'the lower end of one of a series of levers carrying the dampers to be applied tothefstrings insuch a piano. When the loud pedal, or its equivalent in an automatic player, is required, the lower ends of these levers 7 1nust be pushed backward toward the strings to raise the dampers upon their opposite ends. It may be necessary that all the dampers upon the action be raised or that only a. part thereof be raised. In any event the dampers should be raised against the spring action positively, quietly and in certain types of pianos,

they must be held raised automatically until released. Hitherto, locking means for holding the dampers raised has been undesirable because of the noise inherent upon the looking operation, and the present device is particularly designed to hold the dampers raised as long as may be required without any operation which may produce noise and to permit them to lower under the action of their springs quietly, yet quickly, when their use is required. Although the motor is specially designed for this use and was, in

fact, constructed in the first instance for this particular purpose, it is evident that there are many other purposes for which it might conveniently be used, and although it is shown in this connection it is not intended in any way to limit its application.

Referring to the drawings, 8 are fieldmagnets connected by pole-pieces 9, the magnets being so wound and connected, as will be hereinafter explained, that the two ends of the magnets 8 attached to one pole-piece will always be the same polarity, either positive or negative, the case maybe. Thus at all times one pole-piece 9 is necessarily positive and the other negative. Piv'oted between the'field pole-pieces. 9 is an oscillatable armature consisting of a central core 10 terminating in curved shoes 11 of magnetic material and surrounded by the usual coil 12 one terminal of. which is grounded upon the frame and the other terminal of which is led out through a central opening 13 in a shaft 14: which supports the armatrue, so as to make electrical connection with a metal sleeve 15 mounted on the outerend of the shaft 14, but insulated therefrom, and provided with a finger 1G.

For clearer understanding of the operation of the device, it may perhaps be stated at this time, that the electrical connections, hereafter to be described, are of such character that the current always flows in the same as indicated in Figs. 5 and 6, that with the particular battery connection the upper end of the swinging armature is positive, then if a current be thrown through the fields in such a direction as to make the left-hand pole-piece of the field positive, the armature will at once swing to the position shown in; Fig. 2, where it will remain until another reverse ofthe poles upon which it will swing in the opposite di rection'. This is the manner in which the device normally operates to secure the desired results and before proceeding to a description of the electrical-connections whereing the dampers will produce no noise.

At the rear of the armature is a shaft 17 in line with the shaft 1& and this shaft carries a disk 18 provided with a crankpin 19 connected by a link 20- withthe outer end of an arm 21 extended backward from a damper-raising bar 22 supported by radial extensions 23 hung from a part of the frame of the piano. Thus, when the link 20 is depressed the bar .22 is moved from the position shown in Fig. 1 to that shown in Fig. 2 raising the dam pers in an obvious manner. lhe bar 22 is ar. ranged to contact with felt pieces upon the damper-levers so that the operation of raislfhc crank-pin is so disposed upon the disk 18 that when thearmature swings from the position shown in Fig.1 to that shown in Fig. 2, it will swing past the dead-center thus by 'the action of the damper springs holding the dampers in a raised position quietly and efficiently, but they can readily be released and lowered by the reversal of polarity in the pole-pieces 9 caused in an obvious manner.

In order to secure the electrical changes necessary in the operation of the present device, two actions are necessary, and, from an electrical point of View, the two actions may be performed by separate devices, although the separate devicesare united in the preferred form of construction, in the manner hereinafter to be set forth. These separate actions are, first, that upon the movement of the armature fr'om one position to the other, it shall operate a pole-changer, or other equivalent device, so as to reverse the polarity in the field. If this change in polarity aloneoccurs thearmature would immediately'mo've in the reverse direction so that it would perform a constant series of oscillations, but inasmuch as the desired action of the present motor, atleast in its preferred construction, is to have the armature swing to one side and remain there until positively returned by controlling mechanism, it is necessary that the armature in addition to changing the polarity of the field shall break the circuit leaving it ready, however, to be closed by controlling mechanism arranged at a distance.

24 is-a battery, or other source of electric current, one pole of which is by a wire 25 grounded on the frame. The opposite pole is connected by a wire 26 with a switch 27 from which the circuit extends in two parallel branches 28 and 29 tocontact points 30 and 31 mounted on an insulating block 82.

33 and 34 are springs attached to the side of the insulating block 82, said two springs being attached to the two ends of the fieldcircuit and terminating in inwardly-projecting tips 35 and 36, either of which may en with the tip, or finger 16 on the disk 15, carried by the arnmture-shaft 1 1, in ac cordance with the position occupied by the armature. It; will be seen that the oscillatingfinger 16 which moves with the armature, thetwo springs and the contact points 30 and 31 are analogous in arrangement to a very common form of pole-changer except that instead of a single central piece, the two contacts 30 and 31 are substituted, one of which is connected to each branch of the circuit controlled by the switch. By this means the parts perform the double function, as the armature oscillates, of a polechanger, and a two-point or'cut-olf switch adapted to break one branch of the circuit and close the other preparatory to a second operation of the switch 27.

Taking the parts, for instance, in the position shown in Fig. 5, if the switch 27 be thrown to the position shown in dotted lines Fig. 5, the current will flow from the positive pole of the battery to the frame of the machine, thence through the armature to the 'field to the spring 33, the contact point 31, wire 28 and switch 27 to wire 26 and the battery. The magnetism will be that indicated by the signs in Fig. 5, and manifestly the armature will oscillate to the position shown in Fig. 6. This movement will. perform the desired mechanical work, will permit the spring 34- to engage the contact point SO and cause the finger 16 to engage the spring 33, thus reversing the polarity of the field, and by raising the spring 33 from the contact-piece 31 will break that branch of the circuit through which the current has been flowing. If the switch 27 be now rent will flow through the armature as before, then through the finger 16 to spring 33, through the field in the opposite direction, to spring 3 1e, contact-point 30, wire 29, switch and the wire .26 back to the battery.

It will be seen, as already indicated, that the tip 16, the contact-points 30 and 31 and the springs 33 and 34- are in reality a pole- .changer withv the added feature of a double contact so that the throw of the polechanger not only reverses polarity, but breaks one branch'of the circuit and closes the other in'p reparation for the operation of the switch. This being true, a number of simple electrical variations will at once occur to'any one skilled inlthe art. In order ity the polechanger,must affect only the flow through the field, but this can be done in several ways.

I claim as new and desire to secure by Letters Patent 1. reciprocatory-electric motor, comthe tip 16, thence to the spring 3a, through thrown in the opposite direction, the curto maintain the armature of constant polarprising, in combination, a field magnet, an

armature of constant polarity, a single contact-point-oscillated by the movement of the armature, two springs adapted to be alternatively engaged thereby, two stationary contacts, each adapted to be engaged by that spring which is out of engagement with the oscillatorycontact-point, a circuit including two branches, one of which runs to each of the stationary contact-points and a switch controlling; the flow of current to said branches. V

2. An oscillatory-electric motor, comprising, in combination, a, fieldmagnet having field windings, an oscillatory electromagnetic armature, a source of electric ourrent, connections therewith through the ar-- mature whereby the armature polarity remains constant, an oscillatory contact-point carried by the armature and in electrical connection with one'terminal thereof, two movable springs adapted to be alternately engaged by said oscillatory contact-point, connections between said springs and the field winding, two contact-points, each of which is adapted to be engaged by that spring which is out of engagement with the oscillatory contact-point, two parallel circuit-branches connecting the source of ourrent-supply with said two contact-points, and .a switch controlling the flow of current to each branch.

i 3. An oscillatory-electric motor, comprising, in combination, a field-magnet, an oscillatory armature, a crank-pin carried by the armature and arranged as theannature oscillates from one position to another to swing past the dead ,center for holding the. armature in position, means connected to the crank pin and urging the same in an upward direction, a source of electric-current,

- means operated by the oscillations of the armature for reversing the polarity of the field, and acircuit, part of which consists of trolling the flow of current into either branch, and means operated by the movement of the armature for reversing the polarity in the field and breaking one branch of the circuit and closing the other.

5. An oscillatory-electric motor comprising in combination a field-magnet, an oscillatory armature, a crank-pincarried by the armature and arranged as the armature oscillates from one position to another to swing past the dead center for locking the armature in position, means connected to the crank pin and urging the same in an upward direction, a source of current, means operated by the oscillation of the armature for reversing the polarity of one of said magnetic parts, and a circuit part of which consists of two branches, means operated by the oscillation of the armature for breaking one branch and closing the other, and a switch controlling the flow of current through each branch, for the purpose setforth.

In testimony whereof I have hereunto set my hand.

HENRY K. SANDELL.

In the presence of two subscribing witnesses:

v A. U. THoRmN,

R. A. SCHAJEFER. 

